The death investigation, which is now concluded after the medical examiner's ruling, was being conducted by the Cook County Sheriff's Office with assistance from the Arlington Heights Police Department.

Anderson had last been seen at his Arlington Heights Home at 4:30 p.m. Monday, Arlington Heights Police said.

His car was located by the Cook County Forest Preserve Police at the intersection of Donlea and Bateman roads in Barrington Hills near Spring Creek Valley Forest Preserve at 7 p.m. Monday.